P.Hare Royal Aircraft Factory (Putnam)

S.E.5

Although it has occasionally been suggested that the design of this neat and attractive single-seater scout was carried out, at least in part, by Frank Goodden, it is doubtful whether his role extended beyond suggesting features he felt would be desirable, for H P Folland's style is clearly evident in every detail. The S.E.5 was designed around the Hispano-Suiza V-8 engine, which, when it was first unveiled in mid-1915, was universally heralded as a significant advance in engine design. The use of this largely untried 200hp engine, with its reduction-geared propeller, was clearly intended from the start, because the sole armament originally envisaged for the S.E.5 was a Lewis gun mounted between the cylinder heads and firing through a hollow propeller shaft, an arrangement which obviated the need for synchronization gear, which the Allies had yet to perfect. The original drawings show a compact and very conventional tractor biplane, its pilot seated unusually high to give him the best possible view past the upper wing. The vertical tail included both dorsal and ventral fin surfaces and a rudder which, save for its rounded corners, was a narrow parallelogram. The control wires to the rudder and elevators were routed wholly within the fuselage to reduce drag. To make the aircraft safe to be flown by inexperienced or inadequately trained pilots, the wings were given generous dihedral angle to afford a reasonable degree of stability, equally generous control surfaces being provided to allow good manoeuvrability. The tailplane incidence could be adjusted, via a control wheel in the cockpit, to trim the machine to fly 'hands off#. One departure from convention, made in the interests of simplified construction, was the omission of compression ribs in the wing structure. Instead, some of the normal aerofoil ribs were formed from solid ply to carry the compression forces. Three prototype S.E.5s were built, the first, A4561, being completed by November 1916. It differed from the original drawings in having the fin and rudder originally designed for the F.E. 10, an unbuilt project also designed around the Hispano engine. As no 200hp engine was available, a direct-drive unit of 150hp was installed in A4561, which was not fitted with any armament. Frank Goodden took it up for its initial flight at about 10.00am on 22 November and, on landing after about ten minutes, exuberantly announced to the waiting spectators, 'She's a pixie!'. Capt Albert Ball, who was allowed to make a short flight the following day while on a visit to Farnborough, was less enthusiastic, comparing the new machine unfavourably with the lightness of the rotary-powered Nieuport which was then his usual mount. However, he was later to revise his opinion. The second prototype, A4562, which appears to have been identical to the first, was test flown, again by Goodden, on 4 December. A heavy landing during subsequent testing necessitated a replacement undercarriage, and while it was in the workshop the machine was fitted with what would become the type's service armament. A belt-fed Vickers gun was mounted in the forward fuselage decking, offset to port and inclined at five degrees above the line of flight to lessen the effects of bullet drop and extend the effective range. The gun was synchronised to fire through the propeller disc by the recently developed Constantinesco gear. Since this gear could operate only a single gun at that time, a drum-fed Lewis gun was also fitted, on an overwing Foster mounting, firing above the propeller disc. Both an Aldis optical sight and a simple ring and bead were provided, the former directly in the pilot's line of sight and the latter fixed above the barrel of the Vickers gun. The third prototype, A4563, had the 200hp geared engine for which the type had originally been designed, but otherwise differed little from the two previous examples. It made its first flight on 12 January, with Goodden in the cockpit, and, after suitable modification, eventually became the prototype S.E.5a. On 28 January 1917 the port wing cellule of A4562 folded up in flight and its pilot, Frank Goodden, was killed in the resulting crash. A committee of investigation headed by Dr A P Thurston concluded that the wings had failed owing to the inadequate strength of the compression ribs, allied with unsatisfactory attachment of the interplane struts to the spars, which had allowed the former to become detached. The Factory staff quickly redesigned these components and the modifications were incorporated in all production machines, the first batch of which was already well advanced in the newly extended Farnborough workshops. The first production S.E.5, A4845, was tested at Martlesham Heath in March 1917. It was criticised both for its poor lateral control at low speeds, and for its huge 'greenhouse' windscreen which, although it was designed to protect the pilot in his rather elevated position, tended to distort his view. Research carried out at the Factory established that the cause of the former deficiency was the sharp outward rake of the wingtips, and plans were made to modify this, thereby reducing the overall wingspan by about fifteen inches. The first unit to be equipped with the S.E.5 was the newly formed 56 Squadron, whose pilots included Albert Ball. Before the CO, Maj Blomfield, would allow the pilots to begin operations, the greenhouse windscreens were removed by squadron personnel and replaced by small flat screens intended for Avros. This modification was eventually made to all S.E.5s, and in addition the pilot's seat was lowered and a faired headrest was fitted. Later aircraft were fitted with long, straight exhaust pipes discharging aft of the cockpit, in place of the original 'T' shaped manifolds and stub exhausts. Radiator shutters, operated by the pilot, were added to assist in controlling engine temperature. Only fifty or so machines had been completed when the decision was taken to fit all future machines with the 200hp engine, which was finally expected to become available in quantity. The shorter-span wings were also to be adopted at the same time, machines thus equipped being designated S.E.5a.

The third prototype S.E.5, A4563, which had been fitted with a 200hp geared Hispano-Suiza at the time of its first flight in January 1917, was subsequently modified in an effort to overcome the defects noted in the Martlesham Heath report on the type. It therefore had the shorter-span wings, an internal gravity petrol tank and water header tank within the centre-section, a lowered pilot's seat and a faired headrest. Although no criticism appears to have been made of the original two-bladed propeller, a four-bladed unit of slightly reduced diameter was substituted, in accordance with common Factory practice. On 29 May Roderic Hill flew the modified aircraft to Martlesham Heath, where it received lightly favourable and enthusiastic reports. All production orders placed were therefore for the new type, now given the designation S.E.5a. The aircraft industry was already swamped with work, and although Martin and Handasyde and the Air Navigation Company accepted orders, the majority went to companies previously engaged in other fields of engineering, including Wolseley Motors and Austin. Production was also undertaken by the Royal Aircraft Factory, and by the end of 1917 almost a thousand airframes had been produced. Unfortunately, owing to problems with the geared engine, and consequent delays in manufacture, more than 400 machines were stockpiled awaiting engines. In an effort to forestall this eventuality an order had been placed with Wolseley for a number of direct-drive engines. However, because of a misunderstanding, instead of producing licence-built examples of the well-proven 150hp version which powered the S.E.5, the company set about developing an uprated version, intended to give the same output as the unreliable geared variant. By increasing the compression ratio from 4.5:1 to 5.6:1 it became possible to obtain 220hp at 2,000rpm, although this speed was rather high by the standards of the day. An example of this new engine, named the Viper, was tested in a production S.E.5a, after which its compression ratio was slightly reduced to 5.3:1. Although this lowered the nominal power output to 200hp, it gave a slightly enhanced performance at altitude and was adopted for production. A geared version, with the same rating but a lower propeller speed, was also produced, although in much smaller quantities. To facilitate the installation of whichever of these engines was available, a new radiator, split into two separate banks each with its own shutters, was developed. This left a central vertical slot which could accommodate the different thrust lines of the various engines. The new radiator, which gave the machine a more purposeful, aggressive appearance, was fitted to all Wolseley-powered aircraft, stocks of the original one-piece radiator being used up on the Hispano-powered machines for which it had been designed. Hispano-powered S.E.5as also had small fairings over the ends of the projecting cylinder heads, while those with the Wolseley, which projected slightly less, did not. Machines with geared engines, of whatever make, were fitted with four-bladed propellers, and had a modified Foster mounting for their overwing Lewis guns to allow for the higher thrust line. While the engine shortage was at its most acute a small number of S.E-.5as were fitted experimentally with the 200hp Sunbeam Arab, but this unit proved less reliable than the Hispano it was intended to replace, and was not adopted for mass production. Complaints that the original steel-tube undercarriage lacked sufficient resilience for unprepared fields led to the development of a new type, with twin front legs in a narrow inverted vee, all encased in wooden fairings. Another, all-wood version was found to be equally successful and, being far simpler to produce, was adopted thereafter. Overall, the S.E.5a was a great success, being strong, easy to fly, a stable gun platform, and possessing a performance at least equal to that of any adversary. Its success as a fighter, measured in terms of combat victories, was second only to that of its 'rival', the Sopwith Camel, but the Camel was a much trickier machine to fly and had an unenviable reputation for killing inexperienced pilots. Marshal of the Royal Air Force Lord Douglas of Kirtleside, who flew the type in 1917/18, said in his autobiography, 'Many of us felt that it was the best fighter in Britain in the First World War'. He described it as 'a very strong aeroplane', and 'the most beautiful aeroplane that has ever been built'. Despite the S.E.5a's acknowledged success, the Factory continued to explore ways of enhancing its performance. In one experiment the S.E.5 A4862, which had remained at Farnborough and been converted to S.E.Sa configuration, had its nose covered by a blunt fairing, the car-type radiator being replaced by an underslung radiator beneath the fuselage. This appears to have been formed by mounting two Viper-type radiator blocks together, one above the other. As no significant improvement in performance resulted, the modification was not adopted, especially as the car-type installation was slightly easier to produce. Various alternative tail surfaces were designed, including one with twin fins and rudders and another with a rounded vertical tail which gave the machine a vaguely Teutonic appearance. None of these was adopted, and, as no particular criticism appears to have been levelled at the aeroplane's existing tail surfaces or its control or stability, it can only be assumed that the installations were part of a programme of 'pure' research, in keeping with the Royal Aircraft Factory's redefined role. However, one tailplane modification which was adopted, although for relatively few machines, was the use of elevators of reduced chord. These were designed to increase manoeuvrability, but appear to have had little effect. To facilitate pilot training a number of S.E.5as were converted to dual-control two-seaters. The main petrol tank was drastically reduced in size to make room for the second cockpit, which was positioned under the centre section, and no armament was carried. Tests were carried out with a variable-pitch propeller, at least one machine being so equipped, but no real success was achieved during the existence of the Royal Aircraft Factory. By the time of the Armistice 5,205 S.E.5as had been completed, the total reaching 5,269 before production finally ceased. After the war the type continued to serve with the United States Air Service and South African Air Force. Those belonging to the Royal Air Force were quickly disposed of, and a number found their way on to the civil register, at least one being powered, in the interests of economy, by an 80hp air-cooled Renault, with which the top speed fell to about 65mph. Apart from pleasure and sporting use, the S.E.5a pioneered the art of 'skywriting' both in England and in the USA, a use which served to ensure that three examples would be preserved for posterity in England. Two more survive in the museums of the Australian and South African air services, and two American Eberhart-assembled examples are also extant.

Early in 1918 A8947, the last of a batch of Farnborough-built machines, which had been ordered as an S.E.5 but completed as an S.E.5a, was modified to become the S.E.5b. New wings of unequal span and chord were fitted, the upper-wing ailerons being of narrow chord and hinged from an auxiliary spar. The interplane struts were raked outwards. The nose was streamlined, a large shallow spinner covered the propeller boss, and a retractable underslung radiator was provided to cool the 200hp geared Hispano-type engine. Testing revealed that the induced drag of the large upper wing offset any advantage gained by the streamlining of the nose, and the anticipated improvements in performance were not realised. Some time after the Armistice it was fitted with standard S.E.5a wings of equal span and chord, and was tested against a production S.E.5a with a nose radiator. The production machine was found superior in powered flight, the modified machine only bettering its performance when gliding with its radiator retracted.

After the war the Eberhart Company in the USA assembled about sixty S.E.5as, largely from spare parts, for use by the US Air Service. These had plywood-covered fuselages and were powered by direct-drive 180hp Hispano-Suizas built under licence by the Wright Company. The designation S.E.5E has frequently been applied to these machines.

This was to have been a single-seater scout for which both the Rolls-Royce Falcon and the supercharged R.A.F.4d have been suggested as possible powerplants. It was to have had equal-span wings separated by 'N' struts. It is doubtful whether anything other than preliminary sketches were made, and no drawing connected with it has survived.

S.E.7

The S.E.7 appears to have been a radial-powered variant of the S.E.6, with which it is known to have shared its wings and tail surfaces. The projected engine was the R.A.F.8, for which a long-chord cowling was developed by windtunnel tests upon scale models. The design was not completed, but it may have formed the basis for the S.R.2, designed by the Siddeley Deasy Company, of which Fred Green was then chief engineer and where the R.A.F.8 engine was developed into the Jaguar.

T.E.1

The T.E. classification was originally an abbreviation of 'Tatin Experimental', and was therefore reserved for aeroplanes with propellers behind their tails, but no machines of that type were built. In the case of the T.E.1 there is no record of what the 'T' stood for, the aircraft being a two-seat 'fighter' based upon a scaled-up S.E.5. The drawings, completed early in 1917, show the machine with the now-universal variable-incidence tailplane and a steerable tailskid. Its intended armament was to have been a forward-firing Vickers gun fitted with the Constantinesco synchronisation gear, and a Scarff-ring-mounted Lewis for the observer. Power was to be provided by a 200hp Hispano-Suiza, or a variant thereof. Three prototypes were ordered on 23 February, to be completed within three months, and three more examples were planned for later completion. The serials A8951-8956 were allotted to the six aircraft. The first T.E.1 was approaching completion, slightly later than specified, when, on 11 June, work was suspended and was never resumed. The reason has not been discovered, but the emergence of the superb Bristol F.2B Fighter, coupled with the difficulties with production of the Hispano engine, must have influenced the War Office's decision.

P.Bowers Curtiss Aircraft 1907-1947 (Putnam)

S.E.5

The S.E.5 was one of the leading British fighters of 1917 and was one of two European single-seaters chosen by the Bolling Commission for mass production in the United States. It was designed and built at the Royal Aircraft Factory and the letters stood for Scouting Experimental, Model 5. Powerplants were direct-drive and geared versions of the 180-200 hp French Hispano-Suiza and a British-built copy known as the Wolseley Viper. Curtiss was given an order for 1,000 S.E.5s, but only one example was built (US Army serial 43153). Fifty-six others, sometimes referred to as Curtiss SE-5s, were British-built airframes sent to Curtiss for assembly. These were flown as trainers in the US under their original British serial numbers and markings. The single Curtiss-built SE-5, using the Americanized Hispano-Suiza engine as built by Wright-Martin, was delivered to the Army for test in September 1918, and was carried on Army books at a value of $544,716. Additional British S.E.5s, delivered to American pursuit squadrons in France, were brought to the US when those squadrons returned home after the Armistice. These were first-line pursuit aircraft until replaced by new American designs in 1920. In 1923, fifty S.E.5s were sent to Eberhart Steel Products Company for rebuild as SE-5Es (for Wright E engine, the American-made 180 hp Hispano-Suiza) and served with other SE-5s as advanced trainers until 1927.

G.Swanborough, P.Bowers United States Military Aircraft Since 1909 (Putnam)

CURTISS S.E.5A/EBERHART S.E.5E

One of the best known designs selected by the Bolling Commission for U.S. production was the S.E.5A, designed by H. P. Folland in Britain. Planned mass production by Curtiss did not materialize but the company modified and assembled 57 British-built airframes (which retained their British serials). In 1922 and 1923, the Eberhart Steel Products Co. rebuilt 50 S.E.s with 180-h.p. Wright-Hispano Es for use as advanced trainers under the designation of S.E.5E (22-276/325) Span, 26 ft. 9 in.; length, 20 ft. 10 in.; area, 247 sq. ft.; weight, 2,060 lb.; high speed, 122 m.p.h.

O.Thetford Aircraft of the Royal Air Force since 1918 (Putnam)

S.E.5A

One of the outstanding single-seat fighters of the First World War, the S.E. 5A was developed from the S.E. 5 which first entered service with the famous No. 5b Squadron in March 1917. In October 1918 the S.E. 5A equipped Nos. 1, 24, 29, 32, 40, 41, 56, 60, 64, 74, 84, 85, 92, 111 and 145 Squadrons of the R.A.F. One 200-h.p., 220-h.p. or 240-h.p. Hispano- Suiza or 200-h.p. Wolseley Viper engine. Loaded weight, 2,048 lb. Max. speed, 132 m.p.h. at 6,500 ft. Climb, 765 ft., min. Service ceiling, 20,000 ft. Span, 26 ft. 7 1/2 in. Length, 20 ft. 11 in.

H.King Armament of British Aircraft (Putnam)

S.E.5. The weight of armament (100-107 lb) carried by the standard S.E.5 and 5a single-seaters, which fought with such telling effect in harness with the Camel, approximated closely to that carried by the Sopwith fighter, but in type of armament, as in other basic respects, the Royal Aircraft Factory product differed widely. From the beginning the S.E.5 design was associated with the Lewis gun. As will be explained in Volume 2, the idea of a fixed gun firing through the hollow airscrew shaft of an engine was an early British idea, though not, it appears, as early as Louis Bleriot's scheme for such an installation in 1911. This same arrangement was adopted in the summer of 1916 for a proposed tractor single-seal fighter designated S.E.5, an alternative design to another, designated F.E.10, which perpetuated the B.E.9 theme, but which was mercifully abandoned in favour of the S.E.5. The Lewis gun in the early S.E.5 design was to fire between the cylinder banks of the Hispano-Suiza engine and through the hollow airscrew shaft. The 47-round magazine was envisaged. This scheme was abandoned, and by December 1916 the second S.E.5 was fitted with a basic armament which set the standard pattern, namely a Lewis gun on a Foster mounting above the centre-section and a synchronised Vickers gun semi-internally to port. There is good reason for supposing that the large 'greenhouse' windshield associated with the earliest S.E.5s was adopted to facilitate the changing of ammunition drums, for the lower end of the quadrant which constituted the rear member of the Foster mounting, and down which the gun was swung for reloading or upward firing, was anchored to the top of the canopy; thus, with the gun at its lowest position, the drum was largely shielded from the slipstream. Certainly the changing of 97-round drums in later S.Es, which had ordinary windscreens, could be a difficult business, almost, on occasions, breaking a pilot's wrist. The large windshield was perforated to starboard to receive the eyepiece of the Aldis sight, the rear clamp for which was attached to the windshield framework, and the front one to a substantial pylon on the fuselage decking. The Vickers gun, which had a Type A trigger motor for the Constantinesco gear, was recessed into the main petrol tank. There was an ejection chute in the port upper cowling. When a plain windscreen was fitted it became necessary to modify the fuselage decking to enclose the breech casing of the gun. Capt Albert Ball, whose ideas may well have influenced the adoption of the Lewis gun and Foster mounting for the S.E.5, quickly discarded the Vickers gun on his aircraft, but mounted instead a second Lewis gun, firing downwards through the bottom of the fuselage. Later this gun was discarded in turn, and the Vickers gun was reinstated, though it was now wholly external, presumably because the earlier gun-trough had been replaced by increased petrol capacity. On Ball's aircraft the lower end of the Foster mounting was braced by two wires, but a tubular structure was standardised. So that the lines of fire of the two guns could converge at a range of 50 yards, the Foster mounting was slightly raised at its rear end.

S.E.5a and b The S.E.5a had the 200-hp Hispano-Suiza engine, and the larger airscrew needed to absorb this greater power caused the Foster mounting to be raised very noticeably above the wing on two supports, over the front and rear spars. For the Lewis gun on this mounting, one ammunition drum was carried on the gun and three in the cockpit. For the Vickers gun, which, on late aircraft at least, had the Type B trigger motor on top of the gun and the Hyland Type E loading handle, there were 400 rounds. Both guns were aligned 5 degrees up from the line of flight. Fitzgerald jam-clearers have been mentioned in connection with the S.E.5a. Both Aldis and ring-and-bead sights were fitted, and provision was made under the fuselage for a four 20-lb bomb-carrier. Two 20-lb bombs are known to have been carried loose in the cockpit. Early troubles were experienced with the Constantinesco gear, but the S.E.5a proved an exemplary gun platform. Fire could thus be opened at relatively long range, and there is a reference to the guns being set for their lines of fire to converge at 200 yards. A distinctive feature of the S.E.5a was the gear wheel and the associated 'box' type generator for the Constantinesco gear, visible beneath and behind the airscrew hub. No.41 Squadron is said to have attempted to install twin Vickers guns, and one machine had twin Lewis guns. There was, too, an experimental installation of the Eeman triple-gun mounting, wherein the three Lewis guns fired forwards and upwards through apertures in the centre-section. A report that an installation of a rearward-tiring Vickers gun was made in 1917 cannot be corroborated. At least one night-flying example had a greatly lengthened pistol grip on the Lewis gun. The S.E.5b appears to have been armed as the standard S.E.5a.

G.Swanborough, P.Bowers United States Navy Aircraft Since 1911 (Putnam)

R.A.F. S.E.5A

British-built S.E.5A fighters were among the foreign types acquired by the US Navy in 1918 in France. They served in original British colours, with the RAF roundels overpainted in American colour sequence and at least one S.E.5A in these markings operated off a turret on the USS Mississippi after the end of the War. Power plant, one 200hp Hispano-Suiza. Span, 26 ft 7 1/2 in; height, 20 ft 11 in; gross weight, 2,058 lb; max speed, 123 mph.

W.Green, G.Swanborough The Complete Book of Fighters

ROYAL AIRCRAFT FACTORY S.E.5 UK

Second only to the Sopwith Camel in reputation as the RFC's outstanding fighter of World War I, the S.E.5 was designed under the direction of H.P. Folland. Of classic tractor biplane configuration, the S.E.5 was initiated to take advantage of the new Hispano-Suiza engine that began test-running in Spain in February 1915 and was in production in France a few weeks later. Two versions of the engine became available during 1916, the basic direct-drive 150 hp unit and a geared version producing 200 hp. Examples of both were included in the British orders placed in France and, subsequently, with Wolseley for licence-built examples (as the 150 hp Python and 200 hp Adder respectively). The S.E.5 was intended, from the outset, to be powered by the 200 hp geared engine and to be armed with a 0.303-in (7,7-mm) Lewis machine gun firing through a hollow propeller shaft, but, in the event, early aircraft had to use the 150 hp Hispano 8Aa, and had an armament of one Vickers gun in the front fuselage, offset to port, with interrupter gear, and a Lewis on a Foster mount above the centre section. Unarmed, the first of three prototypes of the S.E.5 flew on 22 November 1916. It was a compact single-bay biplane with equi-span wings featuring raked tips, a similarly-raked tailplane, triangular fin and almost rectangular rudder, with a small ventral fin and a V-strut undercarriage. A large windscreen was provided over the front of the cockpit. All major components were of conventional wood construction, with fabric covering. Of two further prototypes, one was similarly powered and first flew on 4 December 1916, whereas the other introduced the 200 hp engine and became, effectively, the prototype for the S.E.5a (which see). Production of the S.E.5 was ordered "off the drawing board” with a first batch of 24 built by the RAF at Farnborough, where the first was completed in March 1917. A second batch of 50 followed on, but at least 15 of these were to emerge as S.E.5a’s, and some S.E.5s in service were also modified to have 200 hp engines. In service with the RFC in France by early 1917, production S.E.5s were modified in various ways, particularly by removal of the windscreen. Other changes tried out on S.E.5s to improve the lateral control were consolidated in the S.E.5a.

The third prototype of the S.E.5 flew at Farnborough on 12 January 1917 powered by a 200 hp geared Hispano-Suiza 8B water-cooled eight-cylinder V-type engine, but otherwise similar to the 150 hp-engined earlier prototypes. While production deliveries of the 200 hp engine were awaited, airframe modifications were introduced in the light of early experience with the first production batch of S.E.5s. In particular, the wing rear spars were shortened at the tips to provide greater strength, this serving to blunt the previously raked tips and reduce overall span by 15 1/2 in (39,4 cm). At the same time, lateral control was improved by shortening the levers on the ailerons. With a small Avro-type windscreen in place of the S.E.5's voluminous structure, a small fabric-covered head fairing behind the cockpit, the blunt wings and the standard Vickers + Lewis gun armament, the version with 200 hp engine became the subject of large-scale production as the S.E.5a, starting with part of the second batch S.E.5s already ordered from the RAF. Two hundred more were built at Farnborough itself and, in addition, by the time the war came to an end in November 1918, some 5,125 S.E.5a’s had been built by five companies in less than 18 months: Austin (1,550), Bleriot & Spad (560), Martinsyde (400), Vickers (2,215) and Wolseley (400). Production of the 200 hp Hispano (in several sub-variants, and including licence-production by Wolseley as the W.4B Adder I, II and III) failed to keep pace with this prodigious output, and numerous operational difficulties with the engine enhanced the problem. Consequently, many S.E.5a's were fitted (without change of designation) with the 200 hp direct-drive Wolseley W.4A Viper, a derivative of the French engine. At least six S.E.5a's were flown with the 200 hp Sunbeam Arab I (geared) or Arab II (direct drive) water-cooled eight-cylinder engine in trials at Farnborough, and some production aircraft received high-compression versions of the French-built Hispano-Suiza engine, increasing maximum output to 220 hp. Twenty-two squadrons of the RFC and the US Air Service were flying the S.E.5a by the time of the Armistice, but this brought an end to planned large-scale production by Curtiss in the US when only one of 1,000 on order had been completed (in addition to 56 assembled from British components). Service use continued on a small scale for only a short time after the end of the war, in Australia, Canada and South Africa as well as with the RAF. The following data refer to the S.E.5a with the 200 hp Hispano-Suiza engine.

The final aircraft built at Farnborough against contracts for 74 S.E.5s placed in 1917 was used early the following year for an experimental programme aimed at improving the performance and fighting ability of the type. Fitted with a 200 hp Hispano-Suiza 8B engine and armed with the Lewis and Vickers gun combination of the standard S.E.5a, it had new single-bay wings of unequal span and chord. In addition, a retractable radiator was provided in the forward fuselage, and a large, shallow, propeller spinner was fitted, to combine with a re-profiled cowling and give better streamlining of the fuselage. The head-fairing behind the cockpit was also improved. Tests in 1918 revealed little performance gain or handling benefit, with the extra drag of the big upper wing offsetting gains from the more streamlined fuselage. Standard S.E.5a wings were fitted to the S.E.5b in 1919, as well as a modified horizontal tail, for comparative testing at Martlesham Heath, and this aircraft made an appearance at the RAF Pageant at Hendon in 1920.

Журнал Flight

Flight, May 9, 1918.

THE ENGLISH S.E.V.A. SINGLE-SEATER FIGHTER.SCOUTING EXPERIMENTAL.

The following description and illustrations published in the German aviation journal, "Deutsche Luftfahrer Zeitschrift," appears to be an official German report - as it is arranged in a similar manner to other descriptions of captured British and Allied machines - on the S.E., and should, we think, he of interest.

THIS machine, which is built by Vickers Ltd., carries the number B 507, and in addition to the usual identification marks, a circle and the letter A in white. On the airscrew there is stamped S.E.V.A., from which it is to be assumed that the older machine of similar type, having a 150 h.p. Hispano engine without reduction gear, was designated as S.E.V. Both wings of the single strutter biplane, having an area of 22.8 sq. metres, have a span of 8.15 metres, and a chord of 1.52 metres. The stagger is 0.46 m. The wings are not swept back. The dihedral angle of the wings, which are joined to centre sections, is 171·. In order to improve the view the lower wings are cut away near the body. The angle of incidence of the top wing is 5·, while that of the bottom wing is 6· at the body and 5· at the struts. Both wing spars are of spruce, and are of I section, while the spars of the short roots, which run through the body, are of steel tubing, 45 mm. outside diameter and 1.75 mm. thick. The wing ribs are of the usual type employed on English machines. Webs 1 cm. deep are glued and tacked into the grooves in the flanges, and the two webs are kept apart by vertical laths. There are no special compression struts between the main wing spars, the function of these being performed by leaving some of the ribs with a full strong web. The internal wing bracing is in the form of single stream line wires between the body and the struts. That of the overhanging portions is thick ended wire. The trailing edge of the wings is formed by a wood strip. Between every two ribs are two short false ribs running from the leading edge to the front spar. The wing fabric is stitched to the ribs and is painted a yellowish white underneath and reddish brown on top, as is also the body fabric. On the under side near the trailing edge there are eyelets for equalising the pressure. The centre section struts are steel tubes stream lined with wood fairings. The inter plane struts are of spruce, and are fitted at their ends with sheet steel shoes to which the incidence wires are anchored. The wing bracing is in the form of stream line wires. The lift wires are in duplicate, the landing wires single. Both spars of the upper plane are braced, in addition, by wires between the centre section struts and the outer struts. Non-balanced ailerons are hinged to the rear spars of both upper and lower wings. The fuselage, an ordinary type of girder, has a turtle-back formed by vertical formers. Up to the pilot's seat it is covered with 4 mm. three-ply wood. Longerons and struts are of I-section with the exception of the vertical struts behind the pilot's' seat, which are turned to a circular section. The tail plane, which is cambered on both sides, is so attached to the body that its angle of incidence can be varied during flight from +4.5· to -3·. To this end its front spar is free to oscillate, while the rear spar and its bracing is attached to a tube which can be raised or lowered in the stern post of the body. This tube is secured, with a threaded portion, to a crown wheel mounted on, but free to turn, in the stern post. When the crown wheel is rotated, by means of a hand wheel and cable from the pilot's seat, it raises or lowers the tube, which carries with it the rear spar of the tail plane, thus altering the angle of incidence. The elevator, hinged to the tail plane, takes part in this movement. The elevator cables are led through tail plane and body, whereby air resistance is reduced, but which necessitates, however, two right-angle bends in each cable. Cellon windows in wings and tail permit of inspecting the pulleys. The undercarriage is of the usual type. The wheel axle, which runs right through, is housed between two auxiliary axles. The travel of the axle is not limited. The construction of the tail skid is unusual. This member is swivelled from the stern post and connected to the rudder control cables. A brass shoe is sprung by means of two spiral springs, prevented from buckling by having inside them telescopic tubes. The enclosed Wolseley-Hispano engine was, according to the makers' plate, given its brake test on August 30th, 1917, and develops 206 h.p. at 2005 r.p.m. The air screw is geared down in the ratio 4:3. The exhaust gases are carried away on each side by exhaust pipes running to a point behind the pilot's seat. The engine is so mounted that it is easily accessible when the engine housing has been removed. The radiator forms the nose of the body. Shutters operated from the pilot's seat permit of covering up about half of the radiator. The main petrol tank is mounted behind the engine on the upper longerons. It has a capacity of 120 litres. A gravity petrol tank, holding 17 litres, is mounted between the leading edge and front spar of the centre section of the top plane. An oil tank of 14 litres capacity is built into the body behind the engine. The fuel is sufficient for a flight of two hours' duration at ground level. In the pilot's cockpit. are the following instruments, &c. :- On the right: A box for signal pistols, a switch for the starter, a change-over switch for the two magnetos, and a lever for adjusting the spiral springs regulating the elevator. In the centre: Altimeter, hand pump, oil pressure gauge, compass, inclinometer, three-way cock for gravity and pressure petrol feeds, three-way cock for hand and motor air pumps, cooling water thermometer, petrol gauge on back of main petrol tank, manometer for air pressure. On the left: Gas lever, lever for regulating the mixture, cable for regulating the radiator shutters, rack for three signal cartridges. On the floor is mounted a hand pump for the hydraulic sighting of the machine gun, two boxes for drums for the movable machine gun, and the starter.

In front of the pilot's seat is a wind screen of triplex glass. Behind the pilot's seat is a box, accessible from outside, running right through the body from side to side. The fixed machine gun is mounted to the left of the pilot, inside the body covering. The cartridge belt is of metal. The firing of the gun is operated hydraulically by a control mechanism in front of the engine, driven by spur gearing on the propeller. The trigger is mounted on the control lever. Mounted on a bent rail above the centre section of the upper plane is a Lewis machine gun, which can be pointed to fire upwards during flight. The weight of the machine empty was ascertained to be 706 kg. The weight of the fuel, with full tanks, amounts to 111 kg., so that the total useful load may be put down as 250 kg., thus giving a total weight of 956 kg. The wing loading is therefore 956 : 22.8 = 42 kg. sq. metre, and the engine loading 956 : 200 = 4.78 kg. h.p.

Major Frank Gooden, a Farnborough test pilot, in the cockpit of the first S.E.5, Folland's renowned World War I fighter.New fighters under design in 1916 began to make their appearance: SE5 prototype A4561 had first flown in November 1916 and the following month was in France for pilot evaluation. It was generally well liked but there were problems, some of which had not been resolved when the first production aircraft were delivered in March 1917.

This machine is most probably A4864, and was originally built as an S.E.5. It has the low thrust line of the ungeared engine, but the long exhaust pipes and all-wood undercarriage of later examples. The curved headrest is unusual.

Aircraft of the second SE5 production batch were given the larger windscreen - giving a semi-enclosed cockpit - but this was not liked by the operational pilots as it was thought to be too restrictive. A8904 is see here at Farnborough in April 1917; it subsequently became operational with 56 Squadron and flew its first combat patrol on May 6.

The Royal Aircraft Factory SE 5, powered by a 150hp direct drive Hispano-Suiza, initially took to the skies on 22 November 1916. Carrying a two-gun armament of one fixed, nose mounted, synchronised .303-inch Vickers, plus a .303-inch Lewis mounted above the wing that could be locked to fire ahead of the aircraft, or freed to swing through a limited arc of elevation, enabling the pilot to rake an enemy's underside. Virtually viceless in terms of pilot handling problems and capable of 122mph at 3.000 feet, decreasing to 116mph at 10,000 feet. The operational ceiling of the SE 5 was 17.000 feet, while the single seater could reach 10,000 feet in 13 minutes 40 seconds. Most of the 59 SE 5s built went to No 56 Squadron, RFC, commencing in March 1917, prior to their appearance on the Western Front the following month. These interim SE 5s were soon to be replaced by the more powerful SE 5a, arguably the finest of Britain's World War I fighters. This rearward aspect on SE 5, A8913 helps emphasise the use of broad chord ailerons on both upper and lower wings - a feature that improved the aircraft's 'rollability'

An unidentified S.E.5a with the early form of undercarriage. Note the higher thrust line of the geared engine, which necessitated a modified Foster mounting to prevent the bullets from its over-wing Lewis gun striking the propeller.

PRESENTATION OF AEROPLANES AT BROOKLANDS ON JULY 6TH. - One of the machines presented by the Hon. H. Burton, K.C., a representative of the Union of South Africa, to the R.A.F., and accepted by Major J. L. Balrd, Parliamentary Secretary of the R.A.F.

Dispersal shot of 6 Squadron AFC with SE5a at Minchampton in spring 1918. All four of the last Australian Squadrons (Nos. 5 to 8) were still working up to operational status during 1918 and did not see active service in France.

THE GERMAN OFFENSIVE ON THE WESTERN FRONT IN FRANCE. - R.A.F. scouting squadron, who fly low to use their machine guns on the enemy masses.32 Squadron arrived in France in May 1916 and spent the rest of the war as a fighter unit, acquiring a distinguished reputation. Here, in early 1918, the crews stand with their SE5a aircraft.

Despite being beset with a series of engine-related problems the 200hp Hispano-Suiza-powered Royal Aircraft Factory SE 5a gave more than a good account of itself when measured against the later Fokker D VII and Pfalz D XII single seaters that it would encounter from the spring of 1918 onwards. With a top level speed of 137.5mph at sea level, plus an ability to reach 10.000 feet in 11 minutes, the first SE 5a operational deliveries commenced in June 1917. Sadly, the engine troubles, coupled to engine non-availability acted as a bottleneck to the numbers of SE 5as that could be fielded well into 1918, the problem only really being resolved with the emergence of the 200hp Wolseley Viper, a British development of the original French engine. Total SE 5 and SE 5a production reached 5.205 machines by war's end, with Curtiss in the US contracted to produce a further 1.000 for the Americans. While all but one of the Curtiss order were to be cancelled with the Armistice, 56 British SE 5a deliveries were made to the Americans. The SE 5a seen here is serial no B4897.

111 Squadron also used the SE5a. as with C1764 here. The Squadron had lormed at Deir-el-Belah in August 1917 as a fighter unit to support the planned autumn offensive. The SE5a was first used from October.

S.E.5a (D5995) of No 143 Squadron while on Home Defense duty at Throwly in 1918. The White on the rudder and roundels have been toned down and a flame damper has been added to the exhaust for night fighting

The SE5a was one of the classic British fighters and was a direct follow-on from the SES; the type entered service in the spring of 1917 and, despite a number of engine problems, was an immediate success.

A fine air-to-air study of the Shuttleworth Collection's S.E.5a, G-EBIA/F904, taken on April 11, 1977, shortly after its first flight following the replacement of the geared 200hp Hispano-Suiza engine by a direct-drive 200hp Wolseley Viper.

Without question the SE 5a was the finest design to come from the Royal Aircraft Factory during its entire existence. The creation of Henry Folland's fertile mind, the SE 5 series of single seat fighters were both heavier and faster than the Sopwith Camel, which they also preceded into operational service. Despite the long standing claim that the Camel downed more enemy aircraft than its rival, which machine was the best will remain a matter of controversy similar to the Hurricane, versus Spitfire question of the next World War. Certainly, while advocates of the SE 5 have to bow to the Camel's quantative 'kill' superiority, they can point to the generally more pilot friendly handling of the SE 5 and speculate about the Camel's 'kill rate' and on which side of the balance sheet to include all of its own pilots that the unforgiving Camel killed.

An unidentified S.E.5a fitted with an experimental low-aspect-ratio fin and rudder of remarkably Teutonic appearance. The handle of the starting magneto is visible just below the exhaust pipe, where it could be operated either by the pilot or by a mechanic standing alongside.

A couple of the aeroplane-building departments of Wolseley Motors, Ltd., illustration of which has hitherto been restricted under Dora. One of these shows an erecting shop with a batch of S.E. 5's in course of construction, whilst in the other the S.E. 5's are being fitted with Wolseley "Viper" engines. It hardly needs emphasising that the Wolseley company supplied a very large number of these machines during the War, and the work of these little single-seater fighting planes, fitted with a Vickers gun in the fuselage and a Lewis gun in the top plane, was very remarkable, and had an appreciable effect upon the final collapse of the enemy.

The nearest line of S.E.5as in production display a cut-out in the forward bulkhead for the Vickers gun. In the second line the Vickers gun is already installed, at least in the aircraft the Service number of which is largely visible. In the third line the Foster mounting is in place. Note access panel for Vickers gun, with built-in ejection chute, on two aircraft at top right.

A corner of a batch of machines, chiefly S.E.5's, for disposal at Hendon. These are a varying quantity, the numbers being added to each day, whilst those disposed of balance more or less the new-comers.

An S.E.5a cockpit, showing the Aldis optical gunsight directly in front of the pilot, and the Vickers gun offset to port. The exhaust pipes have been shortened, leaving a redundant support bracket on the fuselage side below the Vickers gun.

James Thomas Byford McCudden is seen here seated in the cockpit of his Royal Aircraft Factory SE 5a, McCudden, born on 25 March 1895 in Gillingham, Kent, came up through the enlisted ranks to became Britain's most highly decorated airman of World War I. Entering the British Army's Royal Engineers as a boy bugler in 1910, McCudden was to die a major six years later. As with a number of other fighter aces from both sides of the line, McCudden's flying career started as an observer and graduated into piloting two seat Royal Aircraft Factory FE 2d reconnaissance machines with No 20 Squadron, RFC in July 1916 for a few days, prior to joining the single seat Airco DH 2-equipped No 29 Squadron, RFC, on 1 August 1916. Before the month was through, McCudden, a cool, analytical pilot, had opened his tally of downed enemy aircraft by dispatching a two-seat Hannover CL III. Indeed, McCudden, like Manfred von Richthofen and many other aces, tended to specialise in stalking two seaters, 'killing' no less than 45 of these machines out of his confirmed overall score of 57. Commissioned on 1 January 1917, McCudden was invited to join the hand-picked Royal Aircraft Factory SE 5a-equipped No 56 Squadron, RFC, joining the unit as a Captain and Flight Commander on 15 August 1917. By the end of 1917, McCudden had taken his victory score to 37, adding a further 20 between 1 January 1918 and 16 February 1918, when he was posted home. On 6 April 1918, McCudden, already the proud holder of the Distinguished Service Order and bar, the Military Cross and bar, along with the Military Medal, was awarded Britain's highest military recognition for valour, the Victoria Cross. On 9 July 1918, the newly promoted Major James McCudden, Commanding Officer designate of No 60 Squadron, RFC, suffered an engine failure on take off for France, spinning in to his death while attempting to return to the airfield.

Some unique sketches of aircraft at work overseas by Captain K. H. Riversdale Elliot, Scottish Rifles and R.F.C.. The drawings are particularly accurate and full of movement, and carry the greater weight as from an active pilot.